Bilateral Pneumonia in a Patient with Chronic Bronchiectasis Caused by Achromobacter xylosoxidans Subspecies denitrificans

Achromobacter xylosoxidans is a gram-negative bacillus that has a multitude of inherent and acquired antimicrobial resistance. It is a rare, isolated pathogen in patients without cystic fibrosis (CF). We report the case of a 76-year-old Caucasian male with a history of chronic obstructive pulmonary disease (COPD), previous Mycobacterium-avium intracellulare (MAI) infection, and chronic bronchiectasis who did not respond to three courses of outpatient antibiotics for a chronic cough. He also had a 21-lb weight loss. The diagnosis of Achromobacter xylosoxidans subspecies denitrificans was made through bronchoscopy with bronchoalveolar lavage (BAL). There are few case reports describing Achromobacter xylosoxidans subspecies denitrificans in non-CF patients. Achromobacter xylosoxidans colonization might be linked to predisposing lung damage such as in CF and bronchiectasis. The bacterium is frequently multidrug-resistant. More studies are needed to develop recommendations for clinical guidelines to address the increasing antibiotic resistance to Achromobacter xylosoxidans.